From d7955ce24d294fb2014c59d11fca184471056f44 Mon Sep 17 00:00:00 2001 From: Shuyi Chen Date: Wed, 22 May 2013 14:51:55 -0700 Subject: Add android smack source. Change-Id: I49ce97136c17173c4ae3965c694af6e7bc49897d --- src/org/xbill/DNS/ClientSubnetOption.java | 175 ++++++++++++++++++++++++++++++ 1 file changed, 175 insertions(+) create mode 100644 src/org/xbill/DNS/ClientSubnetOption.java (limited to 'src/org/xbill/DNS/ClientSubnetOption.java') diff --git a/src/org/xbill/DNS/ClientSubnetOption.java b/src/org/xbill/DNS/ClientSubnetOption.java new file mode 100644 index 0000000..4a98a12 --- /dev/null +++ b/src/org/xbill/DNS/ClientSubnetOption.java @@ -0,0 +1,175 @@ +// Copyright (c) 1999-2004 Brian Wellington (bwelling@xbill.org) + +package org.xbill.DNS; + +import java.net.*; +import java.util.regex.*; + +/** + * The Client Subnet EDNS Option, defined in + * http://tools.ietf.org/html/draft-vandergaast-edns-client-subnet-00 + * ("Client subnet in DNS requests"). + * + * The option is used to convey information about the IP address of the + * originating client, so that an authoritative server can make decisions + * based on this address, rather than the address of the intermediate + * caching name server. + * + * The option is transmitted as part of an OPTRecord in the additional section + * of a DNS message, as defined by RFC 2671 (EDNS0). + * + * An option code has not been assigned by IANA; the value 20730 (used here) is + * also used by several other implementations. + * + * The wire format of the option contains a 2-byte length field (1 for IPv4, 2 + * for IPv6), a 1-byte source netmask, a 1-byte scope netmask, and an address + * truncated to the source netmask length (where the final octet is padded with + * bits set to 0) + * + * + * @see OPTRecord + * + * @author Brian Wellington + * @author Ming Zhou <mizhou@bnivideo.com>, Beaumaris Networks + */ +public class ClientSubnetOption extends EDNSOption { + +private static final long serialVersionUID = -3868158449890266347L; + +private int family; +private int sourceNetmask; +private int scopeNetmask; +private InetAddress address; + +ClientSubnetOption() { + super(EDNSOption.Code.CLIENT_SUBNET); +} + +private static int +checkMaskLength(String field, int family, int val) { + int max = Address.addressLength(family) * 8; + if (val < 0 || val > max) + throw new IllegalArgumentException("\"" + field + "\" " + val + + " must be in the range " + + "[0.." + max + "]"); + return val; +} + +/** + * Construct a Client Subnet option. Note that the number of significant bits in + * the address must not be greater than the supplied source netmask. + * XXX something about Java's mapped addresses + * @param sourceNetmask The length of the netmask pertaining to the query. + * In replies, it mirrors the same value as in the requests. + * @param scopeNetmask The length of the netmask pertaining to the reply. + * In requests, it MUST be set to 0. In responses, this may or may not match + * the source netmask. + * @param address The address of the client. + */ +public +ClientSubnetOption(int sourceNetmask, int scopeNetmask, InetAddress address) { + super(EDNSOption.Code.CLIENT_SUBNET); + + this.family = Address.familyOf(address); + this.sourceNetmask = checkMaskLength("source netmask", this.family, + sourceNetmask); + this.scopeNetmask = checkMaskLength("scope netmask", this.family, + scopeNetmask); + this.address = Address.truncate(address, sourceNetmask); + + if (!address.equals(this.address)) + throw new IllegalArgumentException("source netmask is not " + + "valid for address"); +} + +/** + * Construct a Client Subnet option with scope netmask set to 0. + * @param sourceNetmask The length of the netmask pertaining to the query. + * In replies, it mirrors the same value as in the requests. + * @param address The address of the client. + * @see ClientSubnetOption + */ +public +ClientSubnetOption(int sourceNetmask, InetAddress address) { + this(sourceNetmask, 0, address); +} + +/** + * Returns the family of the network address. This will be either IPv4 (1) + * or IPv6 (2). + */ +public int +getFamily() { + return family; +} + +/** Returns the source netmask. */ +public int +getSourceNetmask() { + return sourceNetmask; +} + +/** Returns the scope netmask. */ +public int +getScopeNetmask() { + return scopeNetmask; +} + +/** Returns the IP address of the client. */ +public InetAddress +getAddress() { + return address; +} + +void +optionFromWire(DNSInput in) throws WireParseException { + family = in.readU16(); + if (family != Address.IPv4 && family != Address.IPv6) + throw new WireParseException("unknown address family"); + sourceNetmask = in.readU8(); + if (sourceNetmask > Address.addressLength(family) * 8) + throw new WireParseException("invalid source netmask"); + scopeNetmask = in.readU8(); + if (scopeNetmask > Address.addressLength(family) * 8) + throw new WireParseException("invalid scope netmask"); + + // Read the truncated address + byte [] addr = in.readByteArray(); + if (addr.length != (sourceNetmask + 7) / 8) + throw new WireParseException("invalid address"); + + // Convert it to a full length address. + byte [] fulladdr = new byte[Address.addressLength(family)]; + System.arraycopy(addr, 0, fulladdr, 0, addr.length); + + try { + address = InetAddress.getByAddress(fulladdr); + } catch (UnknownHostException e) { + throw new WireParseException("invalid address", e); + } + + InetAddress tmp = Address.truncate(address, sourceNetmask); + if (!tmp.equals(address)) + throw new WireParseException("invalid padding"); +} + +void +optionToWire(DNSOutput out) { + out.writeU16(family); + out.writeU8(sourceNetmask); + out.writeU8(scopeNetmask); + out.writeByteArray(address.getAddress(), 0, (sourceNetmask + 7) / 8); +} + +String +optionToString() { + StringBuffer sb = new StringBuffer(); + sb.append(address.getHostAddress()); + sb.append("/"); + sb.append(sourceNetmask); + sb.append(", scope netmask "); + sb.append(scopeNetmask); + return sb.toString(); +} + +} -- cgit v1.2.3